Wow Peter! That is surprising. Perhaps there is some merit in this idea after all - thanks for the quick comparisons.
Wow Peter! That is surprising. Perhaps there is some merit in this idea after all - thanks for the quick comparisons.
That's very promising. The sample from that hodge-podge setup you put together is close to the Cezanne's. A Nikon d5100 ($700, 16meg) in that setup might best the Cezanne.Originally Posted by Peter J. De Smidt
Imagine what this coming year's 24meg+ mid level cameras would do.
...Mike
What was the aperture and bellows extension?
Adding more pixels may not make any difference at all if it's diffraction limited. Simple solution is to get a faster lens
Generally, regular lens work better than microscope objectives up to 5X. At 10X the microscope objectives are better. A Nikon BD Plan 10x microscope objective's DOF is about 12 microns. Film is about 18 microns thick. A 10X 'scan' of an 8X10 using a 4/3rds sensor would need 360 odd frames without focus stacking and at least 720 frames with focus stacking. An APS-C sensor would only be about 10% more efficient.
Ctein is talking about this on http://theonlinephotographer.typepad...-camera-1.html but at the rate he plods along it will be Summer before he makes an exposure.
Freaking bearded men are slow as molasses. He should get a pipe and get even more relaxed.
Front of the camera to the back of the lens was about 180mm. The lens is an 80mm Rodagon with a fixed aperture. It doesn't say what it is, but my guess is the lens was designed for slide duping at 1:1, with an aperture of F4, but I could easily be wrong. Just in case Bob reads this, it's serial number is 10451006.
Regarding microscope objectives: first off, that's some really neat photography. Second, I'm leaning to el french's view that it might be a little overkill, but if someone has one of these, by all means give it a go. It could be just the ticket for scanning 35mm Tech Pan. I did learn that some of Canon's cameras have a special silent shutter mode that really cuts down on shutter induced vibration. Naturally, I'm committed to the Nikon system. I shot at 1/4 second (main exposure) with an electronic cable release and mirror lock up. As a result, the results could've easily been affected by shutter vibration, especially since I was shooting with a macro bellows on top of a manfrotto 410 head, which was attached to a super clamp hanging on the center post of my tele Studex.
In my tests, I expect that imprecise focusing (and vibration) limited the obtainable quality, and the necessity to re-sample the image limited the usefulness of the comparison shots.
My conclusions, nonetheless, are that the quality was close enough to a very good scanner that the idea still has merit. In addition, alignment was easier than I thought. I simply lowered the lens to light table surface and used the 410's control to make the front of the lens parallel to the light table, and this was just by eye-balling it.
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
Rick, your math is still going awry somewhere. Nyquist tells us that 60 lp/mm requires at the very least 3048 samples per inch (60 * 2 * 25.4).
The original 5D has 121.3 x 121.3 pixels per mm, which as you're suggesting works out to a theoretical max of 60 lp/mm. However, the OLPF, Bayer array and general fudge factor haven't been factored in. Per DPReview, the final number is around 42 lp/mm.
An Epson may be able to capture 42 lp/mm, but it would be buried under such a blurry haze that you'd need to sharpen it to oblivion to find that detail. The Canon gives you that information in a crisp, high-contrast, low-noise image.
I should note that there is an expensive lens (MP-E 65mm) for the Canon system that allows for 5X magnification, so with the 5D, you should be able to capture your negatives at up to 210 lp/mm.
The MP-E 65mm is a nice looking lens, and it's more compact in the field than a bellows unit, but other than that, what would be the advantage of using it over an enlarging lens on a bellows?
Am I right to assume that at 1:1, there's no advantage to reversing a lens?
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
Sounds right. But reversing an enlarger lens optimized for 1:5 would work at 5:1, which might be necessary. But I'll give a try this weekend with a cheap lens that works at 1:1, and compare the results to my scanners. Then I'll know.
Rick "needing a bit of empirical insight with what I can afford" Denney
It looks like the fixed aperture on my Rodagon is F8.5, and so a 50mm 2.8 enlarging lens should do better, especially reversed. Unfortunately, I don't have one any more.
For sensor illumination, the effective f-stop is more important than the set f-stop, but does a smaller effective f-stop also reduce lens aberrations, as stopping the lens down would do?
This isn't directly helpful, but it's fun: http://www.youtube.com/watch?v=XeXjpZpaZns
The following might be more useful: http://thegreatgeekery.blogspot.com/...o-stacker.html
See also: http://www.ebay.com/itm/4-Z-AXIS-SLI...item1e69dd2345
http://www.ebay.com/itm/X-Y-Z-Axis-L...item19cb16f76b
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
There are some good tips in the comments to that article. It looks like many people are working in this direction.
...Mike
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